21002551070 has 32 divisors (see below), whose sum is σ = 37967956416. Its totient is φ = 8364787200.

The previous prime is 21002551021. The next prime is 21002551081. The reversal of 21002551070 is 7015520012.

It is a happy number.

It is a super-2 number, since 2×21002551070² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2762975 + ... + 2770565.

It is an arithmetic number, because the mean of its divisors is an integer number (1186498638).

Almost surely, 2^21002551070 is an apocalyptic number.

21002551070 is a deficient number, since it is larger than the sum of its proper divisors (16965405346).

21002551070 is a wasteful number, since it uses less digits than its factorization.

21002551070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8756.

The product of its (nonzero) digits is 700, while the sum is 23.

The spelling of 21002551070 in words is "twenty-one billion, two million, five hundred fifty-one thousand, seventy".